Question

Which of the following organic compounds polymerizes to form the polyester Dacron ?
a.) Propylene and para $HO - ({C_6}{H_4}) - OH$
b.) Benzolic acid and ethanol
c.) Terepthalic acid and ethylene glycol
d.) Benzoic acid and para $HO - ({C_6}{H_4}) - OH$

Answer 1

Hint: The polymer Dacron consists of a long chain in which repetitive units consist of carboxylic groups at para positions. So, the option that will contain a benzene ring with two carboxylic groups at para positions will be the correct answer.

Complete answer:
These types of questions are easy if we know their answer and can fetch us good marks. These are totally based on the memory of an individual and do not involve any tough concepts that need to be understood.
Let us begin with writing the definition of polymers.
So, a polymer is a substance that consists of many repeating units which are joined in a large chain. These are actually macromolecules.
So, now let us see the options which have the correct combination of substrates.
If we see the options, then the option c.) contains Terepthalic acid and ethylene glycol. This is the correct combination for preparation of polymer Dacron.

Thus, the option c.) is the correct answer.

Note :
Dacron is a synthetic fibre. The polymer possesses high tensile strength and even high resistance to stretching. It has good resistance to degradation by chemical bleaches and to abrasion. So, it has applications in many areas. It is used in yarn which is used for curtains, dress fabric and high pressure fire hoses etc.